int n,m,tot;struct point {double x,y;}p[100000],a[100000],ss;bool cmp(point A,point B){if(A.x!=B.x)return A.x<B.x;return A.y<B.y;}point operator -(point A,point B){point c;c.x=A.x-B.x;c.y=A.y-B.y;return c;}double cross(point A,point B){return A.x*B.y-B.x*A.y;}void dopack(){tot=0;for(int i=1;i<=n;i++){while(tot>1&&cross(p[tot-1]-p[tot-2],a[i]-p[tot-2])<=0)tot--;p[tot++]=a[i];}int k=tot;for(int i=n-1;i>0;i--){while(tot>k&&cross(p[tot-1]-p[tot-2],a[i]-p[tot-2])<=0)tot--;p[tot++]=a[i];}if(n>1)tot--;}bool check(point A){int l=1,r=tot-2,mid;while(l<=r){mid=(l+r)>>1;double a1=cross(p[mid]-p[0],A-p[0]);double a2=cross(p[mid+1]-p[0],A-p[0]);if(a1>=0&&a2<=0){if(cross(p[mid+1]-p[mid],A-p[mid])>=0)return true;return false;}else if(a1<0){r=mid-1;}else {l=mid+1;}}return false;}